186 research outputs found
Diet of Atlantic Sharpnose Shark, Rhizoprionodon terraenovae, from the North-central Gulf of Mexico: Initial Findings Dutch Caribbean: Current Population Status, Fisheries, and Conservation
Effects of awareness that food intake is being measured by a universal eating monitor on the consumption of a pasta lunch and a cookie snack in healthy female volunteers
To date, there have been no studies that have explicitly examined the effect of awareness on the consumption of food from a Universal Eating Monitor (UEM - hidden balance interfaced to a computer which covertly records eating behaviour). We tested whether awareness of a UEM affected consumption of a pasta lunch and a cookie snack. 39 female participants were randomly assigned to either an aware or unaware condition. After being informed of the presence of the UEM (aware) or not being told about its presence (unaware), participants consumed ad-libitum a pasta lunch from the UEM followed by a cookie snack. Awareness of the UEM did not significantly affect the amount of pasta or cookies eaten. However, awareness significantly reduced the rate of cookie consumption. These results suggest that awareness of being monitored by the UEM has no effect on the consumption of a pasta meal, but does influence the consumption of a cookie snack in the absence of hunger. Hence, energy dense snack foods consumed after a meal may be more susceptible to awareness of monitoring than staple food items
Higgs Boson Production in Association with Three Jets
The scattering amplitudes for Higgs + 5 partons are computed, with the Higgs
boson produced via gluon fusion in the large top-quark mass limit. A
parton-level analysis of Higgs + 3 jet production via gluon fusion and via
weak-boson fusion is presented, and the effectiveness of a central-jet veto is
analysed.Comment: 26 pages, 4 Postscript figures, uses JHEP3.cl
Perturbative QCD effects and the search for a H->WW->l nu l nu signal at the Tevatron
The Tevatron experiments have recently excluded a Standard Model Higgs boson
in the mass range 160 - 170 GeV at the 95% confidence level. This result is
based on sophisticated analyses designed to maximize the ratio of signal and
background cross-sections. In this paper we study the production of a Higgs
boson of mass 160 GeV in the gg -> H -> WW -> l nu l nu channel. We choose a
set of cuts like those adopted in the experimental analysis and compare
kinematical distributions of the final state leptons computed in NNLO QCD to
lower-order calculations and to those obtained with the event generators
PYTHIA, HERWIG and MC@NLO. We also show that the distribution of the output
from an Artificial Neural Network obtained with the different tools does not
show significant differences. However, the final acceptance computed with
PYTHIA is smaller than those obtained at NNLO and with HERWIG and MC@NLO. We
also investigate the impact of the underlying event and hadronization on our
results.Comment: Extra discussion and references adde
Difficult Scenarios for NMSSM Higgs Discovery at the LHC
We identify scenarios not ruled out by LEP data in which NMSSM Higgs
detection at the LHC will be particularly challenging. We first review the
`no-lose' theorem for Higgs discovery at the LHC that applies if Higgs bosons
do not decay to other Higgs bosons - namely, with L=300 fb^-1, there is always
one or more `standard' Higgs detection channel with at least a 5 sigma signal.
However, we provide examples of no-Higgs-to-Higgs cases for which all the
standard signals are no larger than 7 sigma implying that if the available L is
smaller or the simulations performed by ATLAS and CMS turn out to be overly
optimistic, all standard Higgs signals could fall below 5 sigma even in the
no-Higgs-to-Higgs part of NMSSM parameter space. In the vast bulk of NMSSM
parameter space, there will be Higgs-to-Higgs decays. We show that when such
decays are present it is possible for all the standard detection channels to
have very small significance. In most such cases, the only strongly produced
Higgs boson is one with fairly SM-like couplings that decays to two lighter
Higgs bosons (either a pair of the lightest CP-even Higgs bosons, or, in the
largest part of parameter space, a pair of the lightest CP-odd Higgs bosons). A
number of representative bench-mark scenarios of this type are delineated in
detail and implications for Higgs discovery at various colliders are discussed.Comment: 31 pages, 5 figure
A complete parton level analysis of boson-boson scattering and ElectroWeak Symmetry Breaking in lv + four jets production at the LHC
A complete parton level analysis of lv + four jets production at the LHC is
presented, including all processes at order O(alpha^6), O(alpha^4*alpha_s^2)
and O(alpha^2*alpha_s^4). The infinite Higgs mass scenario, which is considered
as a benchmark for strong scattering theories and is the limiting case for
composite Higgs models, is confronted with the Standard Model light Higgs
predictions in order to determine whether a composite Higgs signal can be
detected as an excess of events in boson--boson scattering.Comment: More detailed discussion of the effects of the reconstruction of the
longitudinal neutrino momentum. Improved figures. To be published in JHE
How well can the LHC distinguish between the SM light Higgs scenario, a composite Higgs and the Higgsless case using VV scattering channels?
A complete parton level analysis of ll + four jets l = e,mu and 3lv + two
jets production at the LHC is presented, including all processes at order
\ordEW, \ordQCD and \ordQCDsq when appropriate. The infinite Higgs mass
scenario, which is considered as a benchmark for strong scattering theories and
is the limiting case for composite Higgs models, and one example of a model
incorporating a Strongly Interacting Light Higgs are confronted with the
Standard Model light Higgs predictions. This analysis is combined with the
results in the lv + four jets channel presented in a previous paper, in order
to determine whether a composite Higgs signal can be detected as an excess of
events in boson--boson scattering.Comment: Introduced some representative Feynman diagrams. Rearranged section
4. Typos fixed. Published in JHE
Electroweak Radiative Corrections to Associated WH and ZH Production at Hadron Colliders
Higgs-boson production in association with W or Z bosons, p pbar -> WH/ZH +
X, is the most promising discovery channel for a light Standard Model Higgs
particle at the Fermilab Tevatron. We present the calculation of the
electroweak O(alpha) corrections to these processes. The corrections decrease
the theoretical prediction by up to 5-10%, depending in detail on the
Higgs-boson mass and the input-parameter scheme. We update the cross-section
prediction for associated WH and ZH production at the Tevatron and at the LHC,
including the next-to-leading order electroweak and QCD corrections, and study
the theoretical uncertainties induced by factorization and renormalization
scale dependences and by the parton distribution functions.Comment: 32 pages, LaTeX, 21 figures. Uses axodraw.sty and feynarts.sty. Added
reference
Quantum gauge models without classical Higgs mechanism
We examine the status of massive gauge theories, such as those usually
obtained by spontaneous symmetry breakdown, from the viewpoint of causal
(Epstein-Glaser) renormalization. The BRS formulation of gauge invariance in
this framework, starting from canonical quantization of massive (as well as
massless) vector bosons as fundamental entities, and proceeding perturbatively,
allows one to rederive the reductive group symmetry of interactions, the need
for scalar fields in gauge theory, and the covariant derivative. Thus the
presence of higgs particles is explained without recourse to a
Higgs(-Englert-Brout-Guralnik-Hagen-Kibble) mechanism. Along the way, we dispel
doubts about the compatibility of causal gauge invariance with grand unified
theories.Comment: 20 pages in two-column EPJC format, shortened version accepted for
publication. For more details, consult version
A dynamic folded hairpin conformation is associated with α-globin activation in erythroid cells
We investigate the three-dimensional (3D) conformations of the α-globin locus at the single-allele level in murine embryonic stem cells (ESCs) and erythroid cells, combining polymer physics models and high-resolution Capture-C data. Model predictions are validated against independent fluorescence in situ hybridization (FISH) data measuring pairwise distances, and Tri-C data identifying three-way contacts. The architecture is rearranged during the transition from ESCs to erythroid cells, associated with the activation of the globin genes. We find that in ESCs, the spatial organization conforms to a highly intermingled 3D structure involving non-specific contacts, whereas in erythroid cells the α-globin genes and their enhancers form a self-contained domain, arranged in a folded hairpin conformation, separated from intermingling flanking regions by a thermodynamic mechanism of micro-phase separation. The flanking regions are rich in convergent CTCF sites, which only marginally participate in the erythroid-specific gene-enhancer contacts, suggesting that beyond the interaction of CTCF sites, multiple molecular mechanisms cooperate to form an interacting domain
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